The invention relates generally to film magnetic heads, and more particularly to an improved film magnetic head which prevents electrode pad corrosion, thereby improving general reliability. In a film magnetic head, it is desirable to construct the electrode pads of a highly conductive material. As a result, copper (Cu) is typically used in forming the electrode pads of a typical film magnetic head. However, the use of copper presents a corrosion problem as an oxide film can form on each of the electrode pads. When corrosion occurs, it is necessary to polish the surface of each electrode pad before a wire can be bonded to it, resulting in an increased number of manufacturing steps and increased costs.
In addition, after polishing the electrode pads, the film magnetic head is subject to cracking after wires have been bonded to the pads, thus lowering the reliability of the device.
A corrosion prevention method is known in the art in which the copper surface is plated with gold to form a film which prevents electrode pad corrosion. Wire bonding can take place after such plating occurs. However, this method is disadvantageous as it increases the number of required manufacturing steps.
In a conventional film magnetic head, a layer of Ti or Cr is formed on the surface of a conductive metal layer forming the pads. More specifically, in order to secure the adhesion of the conductive metal, layer of Cu or a similar conductor to an insulating layer like SiO.sub.2, an adhesion layer of Ti or Cr is added between the two layers. The section of the insulating layer corresponding to the electrode pad is etched. In the etching process, the appearance of the Ti or Cr layer signifies the complete removal of the transparent insulating layer. Then the layer of Ti or Cr is etched until the conductive metal layer is exposed to form the pad. Etching ends after the Ti or Cr has been completely removed and the Cu layer is exposed.